Fix invalidation during painting of scrollbars

Source/core/layout/compositing/CompositedLayerMapping.h

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 109 matching lines @@
     void setContentsNeedDisplay();
     // r is in the coordinate space of the layer's render object
     void setContentsNeedDisplayInRect(const LayoutRect&, PaintInvalidationReason);
 
     // Notification from the renderer that its content changed.
     void contentChanged(ContentChangeType);
 
     LayoutRect compositedBounds() const { return m_compositedBounds; }
     IntRect pixelSnappedCompositedBounds() const;
 
-    void positionOverflowControlsLayers(const IntSize& offsetFromRoot);
+    void positionOverflowControlsLayers();
     bool hasUnpositionedOverflowControlsLayers() const;
 
     // Returns true if the assignment actually changed the assigned squashing layer.
     bool updateSquashingLayerAssignment(Layer* squashedLayer, const Layer& owningLayer, size_t nextSquashedLayerIndex);
     void removeLayerFromSquashingGraphicsLayer(const Layer*);
 
     void finishAccumulatingSquashingLayers(size_t nextSquashedLayerIndex);
     void updateRenderingContext();
     void updateShouldFlattenTransform();
 
@@ skipping 271 matching lines @@
     unsigned m_pendingUpdateScope : 2;
     unsigned m_isMainFrameLayoutViewLayer : 1;
 
     unsigned m_backgroundLayerPaintsFixedRootBackground : 1;
     unsigned m_scrollingContentsAreEmpty : 1;
 };
 
 } // namespace blink
 
 #endif // CompositedLayerMapping_h